U.S. patent number 8,998,871 [Application Number 11/942,831] was granted by the patent office on 2015-04-07 for absorbent article with compressed channel portions.
This patent grant is currently assigned to Uni-Charm Corporation. The grantee listed for this patent is Kenichiro Kuroda, Yuki Noda. Invention is credited to Kenichiro Kuroda, Yuki Noda.
United States Patent |
8,998,871 |
Kuroda , et al. |
April 7, 2015 |
Absorbent article with compressed channel portions
Abstract
An absorbent article is provided that improves adhesion to the
skin and reduces leaks of bodily fluids by ensuring stable
deformation thereof. The absorbent article has a liquid-permeable
top sheet disposed on body-facing side of the absorbent article; a
liquid-impermeable back sheet disposed on a clothing-facing side of
the absorbent article; and a liquid-retainable absorbent body
disposed between the top sheet and the back sheet. The absorbent
body has a compressed channel formed into a concave shape in the
body-facing side; and a space formed into a convex shape in the
clothing-facing side toward the body-facing. The space is formed on
both sides or on one side of a channel backside located on an
opposing side of the compressed channel portion in the
clothing-facing side.
Inventors: |
Kuroda; Kenichiro (Kagawa,
JP), Noda; Yuki (Kagawa, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Kuroda; Kenichiro
Noda; Yuki |
Kagawa
Kagawa |
N/A
N/A |
JP
JP |
|
|
Assignee: |
Uni-Charm Corporation
(Shikokuchuo-shi, JP)
|
Family
ID: |
39417826 |
Appl.
No.: |
11/942,831 |
Filed: |
November 20, 2007 |
Prior Publication Data
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Document
Identifier |
Publication Date |
|
US 20080119810 A1 |
May 22, 2008 |
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Foreign Application Priority Data
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|
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|
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Nov 22, 2006 [JP] |
|
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2006-316346 |
Nov 22, 2006 [JP] |
|
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2006-316347 |
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Current U.S.
Class: |
604/385.201;
604/385.16 |
Current CPC
Class: |
A61F
13/533 (20130101); A61F 13/4756 (20130101); A61F
13/15707 (20130101); A61F 13/4704 (20130101) |
Current International
Class: |
A61F
13/533 (20060101) |
Field of
Search: |
;604/380,385.101,385.12,385.201 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1805721 |
|
Jul 2006 |
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CN |
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60-69116 |
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May 1985 |
|
JP |
|
09-108262 |
|
Apr 1997 |
|
JP |
|
10-099372 |
|
Apr 1998 |
|
JP |
|
11-299827 |
|
Nov 1999 |
|
JP |
|
11-342154 |
|
Dec 1999 |
|
JP |
|
2000-083992 |
|
Mar 2000 |
|
JP |
|
2001-204759 |
|
Jul 2001 |
|
JP |
|
2001-204760 |
|
Jul 2001 |
|
JP |
|
2001-314445 |
|
Nov 2001 |
|
JP |
|
2002-219144 |
|
Aug 2002 |
|
JP |
|
2003-024372 |
|
Jan 2003 |
|
JP |
|
2004-181085 |
|
Jul 2004 |
|
JP |
|
2006-20977 |
|
Jan 2006 |
|
JP |
|
200668551 |
|
Mar 2006 |
|
JP |
|
325995 |
|
Feb 1998 |
|
TW |
|
329665 |
|
Apr 1998 |
|
TW |
|
371626 |
|
Oct 1999 |
|
TW |
|
Other References
Search Report dated Oct. 16, 2013, directed to EP Application No.
07832400.1; 3 pages. cited by applicant .
Notice of Reasons for Rejection mailed Jul. 3, 2012, directed to
Japanese Application No. 2006-316347; 3 pages. cited by applicant
.
Office Action mailed Jun. 27, 2013, directed to TW Application No.
096144162; 7 pages. cited by applicant .
Notice of Reasons for Rejection issued on Oct. 25, 2011, directed
to Japanese Application No. 2006-316346; 2 pages. cited by
applicant .
Notice of Reasons for Rejection issued on Oct. 25, 2011, directed
to Japanese Application No. 2006-316347; 2 pages. cited by
applicant.
|
Primary Examiner: Hand; Melanie
Assistant Examiner: Craig; Paula L
Attorney, Agent or Firm: Morrison & Foerster LLP
Claims
What is claimed is:
1. An absorbent article comprising: a top sheet having at least a
portion thereof being liquid-permeable and disposed on a
body-facing side; a liquid-impermeable back sheet disposed on a
clothing-facing side; and a liquid-retainable absorbent body
disposed between the top sheet and the back sheet, a portion of the
back sheet defining a planar back face portion of the absorbent
article, wherein the absorbent body comprises: an absorbent core
enveloped in a tissue, the tissue comprising a folded portion at
the body-facing side of the absorbent core along a length direction
of the absorbent article, and the folded portion being configured
to extend when the absorbent core is deformed; a compressed channel
portion formed to be a concave shape in the body-facing side toward
the clothing-facing side; and at least one space having a convex
shape formed in the clothing-facing side toward the body-facing
side; wherein the at least one space is further formed in at least
one side of a channel backside of the compressed channel portion in
the clothing-facing side, and the channel backside projects toward
the clothing-facing side more than the planar back face portion of
the absorbent article.
2. The absorbent article according to claim 1, wherein the
absorbent core is in substantially a center of the absorbent body;
and the space is formed in at least a core side of the opposing
sides of channel backside.
3. The absorbent article according to claim 1, wherein at least a
portion of the top sheet is formed to enable stretching in a width
direction that is perpendicular to a length direction of the
absorbent article.
4. The absorbent article according to claim 1, wherein at least a
portion of the body-facing side in the absorbent body is formed to
enable stretching in a width direction of the absorbent
article.
5. The absorbent article according to claim 1, wherein at least a
portion of the channel backside is bonded to the back sheet.
6. The absorbent article according to claim 1, wherein adhesive
portions are disposed on the clothing-facing back sheet at a side
of the channel backside.
7. The absorbent article according to claim 1, wherein the
absorbent body is configured to be pushed upward by the channel
backside fitting into the spaces.
8. The absorbent article according to claim 1, wherein the top
sheet has a higher ability to stretch in a width direction of the
absorbent article than the absorbent body.
Description
This application claims priority under 35 U.S.C. .sctn.119 from
Japanese Pat. App. Nos. 2006-316346, and 2006-316347, filed on Nov.
22, 2006, which are incorporated herein by reference in their
entireties.
FIELD OF THE INVENTION
The present invention relates to absorbent articles and
manufacturing methods thereof. More particularly, the present
invention relates to absorbent articles that have superior adhesion
and leak-prevention properties, and manufacturing methods
thereof.
BACKGROUND OF THE INVENTION
Conventionally, sanitary napkins, panty liners and urine-collecting
pads, for example, are known as absorbent articles to absorb
excreta such as menstrual blood and the like. Each of these
absorbent articles has an absorbent body that absorbs and retains
menstrual blood and the like; a liquid-permeable top sheet disposed
on a surface on the absorbent article that contacts skin; and a
liquid-impermeable back-sheet disposed on a surface of the
absorbent article that contacts an undergarment. These napkins and
the like are normally worn by being attached to underwear, for
example.
However, for absorbent articles like the one described above, it is
preferred that the absorbing portion of the absorbent body be
placed in close contact to the area of excretion of the wearer to
securely trap excreta that is discharged. The reason for this close
contact is that if a gap is formed, for example, between the
wearer's area of excretion and the absorbent article when the
absorbent article is in use, the excreta can flow along the top
sheet of the absorbent article and leak from the sides of the
absorbent article and reach the buttocks of the wearer. This can
soil the wearer's underwear and undergarments.
Particularly, in the case of a sanitary napkin worn by being
attached to the wearer's underwear, it is easy for the underwear
and area of excretion to become relatively displaced when the
wearer's body moves. This displacing is a cause of side leaks of
excreta. In addition, because a sanitary napkin, for example, is
normally sandwiched between the wearer's underwear and femoral
region, the napkin receives compressing force in a horizontal
direct from the wearer's femoral region causing it to be compressed
and become deformed. The deformation of the absorbent body causes a
gap to form between the wearer's area of excretion and the sanitary
napkin, which results in the wearer's underwear or undergarments
becoming soiled.
Therefore, a sanitary napkin as disclosed in Japanese Unexamined
Patent Application Publication No. 09-108262, which is incorporated
by reference herein in its entirety and hereinafter referred to as
Patent Publication 1, prevents side leaks of excreta and the like
caused by twisting of the absorbent body. That is accomplished by
forming a pair of compressed channels by consecutively
press-treating the top sheet and absorbent body, and equipping each
compressed channel in a length direction of the sanitary
napkin.
The sanitary napkin disclosed in Patent Publication 1 arranges a
pair of compressed channels to sandwich a core portion disposed in
substantially the center in the width direction of the sanitary
napkin, for example. A comparatively high-density compression
portion and low-density compression portion are consecutively
arranged in these compressed channels, thereby forming channels on
the surface side of the sanitary napkin that contacts the skin.
This prevents twisting that extends to the peripheral portions,
even if side compression force is applied from the buttocks of the
wearer causing twisting in substantially the center of the
absorbent body. Therefore, menstrual blood and the like flows out
along this twisting and is prevented from leaking to the sides from
the peripheral portions.
In addition, Japanese Unexamined Patent Application Publication No.
10-99372, which is incorporated by reference herein in its entirety
and hereinafter referred to as Patent Publication 2, discloses an
absorbent article that improves adhesion by the absorbent article
deforming to the wearer's skin by equipping a first flexible shaft
that is emboss-formed from a surface side that contacts the
wearer's skin and bends to the surface side that contacts the
wearer's skin; and a second flexible shaft that is emboss-formed
from a surface side that contacts the wearer's clothing and bends
to the surface side that contacts the wearer's clothing.
The absorbent article disclosed in Patent Publication 2 equips both
the first and the second flexible shafts on the surface sides that
contact the wearer's skin and clothing of the absorbent article.
This makes it easy for the absorbent article to bend to the surface
sides that contact the wearer's skin and clothing when compressing
force is applied from the wearer's buttocks, thereby making it
easier to deform to a desired shape.
However, the sanitary napkin disclosed in Patent Publication 1
disposes compressed channels from substantially the center in the
core thickness direction to the backside surface of the core.
Therefore, pressure transferred from the compressed channels to the
core when compressing force is applied from the wearer's buttocks
in the width direction, and the article spreads in various
directions from the surface sides that contact the skin and
clothing in the thickness direction of the absorbent article. This
causes the core to bend in various directions, which causes the
problem of not being able to always attain a stable
deformation.
Furthermore, the first flexible shaft of the absorbent article
disclosed in Patent Publication 2 is formed in the thickness
direction at the surface side that contacts the wearer's skin more
than the surface side that contacts the wearer's clothing, so force
transferred from the first flexible shaft when a compression force
is applied in the width direction from the wearer's buttocks, and
the absorbent article spreads in various directions in the
thickness direction such to as surface sides that contact the
wearer's skin or clothing. In addition, channels are formed on the
surface side of the second flexible shaft that contacts the
wearer's skin so there is the problem in that a stable deformation
to that surface side is not possible because of the force of the
second flexible shaft acting more in the direction of the clothing
on the surface side that contacts the wearer's clothing.
SUMMARY OF THE INVENTION
The present invention solves the aforementioned problems. An object
of the present invention is to provide an absorbent article that
improves adhesion to the skin and reduces leaks of bodily fluids by
ensuring stable deformation of the absorbent article.
To attain the aforementioned object, the inventors provide
predetermined compressed channels in an absorbent article and a
predetermined space at both sides of a surface side of the
compressed channels that contacts the wearer's clothing to enable
effective deformation of the absorbent article to complete the
invention. Specifically, the absorbent article described below is
provided.
In a first aspect of the present invention, an absorbent article
has at least a portion thereof provided with a liquid-permeable top
sheet disposed on a side of the absorbent article that contacts a
wearer's skin; a liquid-impermeable back sheet disposed on a side
of the absorbent article that contacts the wearer's clothing; and a
liquid-retainable absorbent body disposed between the top sheet and
the back sheet. The absorbent body has compressed channels formed
into concave shapes in the surface side that contacts the wearer's
clothing at the side that contacts the wearer's skin by compressing
from the side that contacts the wearer's skin to the side that
contacts the wearer's clothing; and spaces formed into convex
shapes in the side that contacts the wearer's skin at the side that
contacts the wearer's clothing by compressing from the side that
contacts the wearer's clothing to the side that contacts the
wearer's skin. The spaces are formed on both sides or on one side
of channel backsides that are on an opposite side of the compressed
channels on the side that contacts the wearer's clothing.
In a second aspect of the absorbent article according to the first
aspect of the present invention, the absorbent body has a central
core portion in substantially the center portion thereof, and the
spaces are formed in the central core portion side of at least the
channel backside portions of both sides of the channel
backsides.
In a third aspect of the absorbent article according to the first
or the second aspect of the present invention, the channel backside
portion is formed to project to the surface side that contacts the
wearer's clothing.
In a fourth aspect of the absorbent article according to any one of
the first to third aspects of the present invention, at least a
portion of the top sheet is formed to extend in a width direction
perpendicular to a length direction of the absorbent article.
In a fifth aspect of the absorbent article according to any one of
the first to fourth aspects of the present invention, at least a
portion of the surface side that contacts the wearer's skin in the
absorbent body is formed to extend in the width direction of the
absorbent article.
In a sixth aspect of the absorbent article according to any one of
first to fifth aspects of the present invention, at least a portion
of the channel backside portion is joined to the back sheet.
In a seventh aspect of the absorbent article according to any one
of the first to sixth aspects of the present invention, adhesive
portions are disposed at opposite sides of the channel backside
portions at the surface side that contacts the wearer's
clothing.
In an eighth aspect of the absorbent article according to any one
of the first to seventh aspects of the present invention, the
absorbent body is pushed upward by the channel backside portions
fitting into the spaces.
According to a ninth aspect of the present invention, a
manufacturing apparatus of the absorbent article according to any
one of the first to eighth aspects of the present invention
includes a compressed channel forming means that forms concavely
shaped compressed channels in the surface side that contacts the
wearer's clothing by compressing the absorbent body from the
surface side that contacts the wearer's skin and the surface side
that contacts the wearer's clothing, and convexly shaped spaces in
the surface side that contacts the wearer's skin, in which the
compressed channel forming means has an upper die roller having a
convex portion formed in a predetermined pattern on a surface
thereof; and a lower die roller formed on the surface with a
concave portion that meshes with the convex portion, to manufacture
an absorbent article that is formed with compressed channels and
spaces by compressing the absorbent body using the upper die roller
and the lower die roller with at least the absorbent body in a
clamped state.
According to a tenth aspect of the present invention, a
manufacturing method of the absorbent article according to any one
of the first to eighth aspects of the present invention includes a
compressed channels forming process that forms concavely shaped
compressed channels in a surface side that contacts the wearer's
clothing by compressing the absorbent body from the surface side
that contacts the wearer's skin and the surface side that contacts
the wearer's clothing, and convexly shaped spaces in the surface
side that contacts the wearer's skin, in which the compressed
channels forming process has an upper die roller having a convex
portion formed in a predetermined pattern on a surface thereof; and
a lower die roller formed on the surface with a concave portion
that meshes with the convex portion, to manufacture an absorbent
article that is formed with compressed channels and spaces by
compressing the absorbent body using the upper die roller and the
lower die roller with at least the absorbent body in a clamped
state.
Thus, the present invention provides an absorbent article that
improves adhesion to the skin and reduces leaks of bodily
fluids.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will become more readily apparent from the Detailed
Description of the Invention, which proceeds with the reference to
the drawings, in which:
FIG. 1 is an elevation view of a sanitary napkin according to a
first embodiment of the present invention;
FIG. 2 is a backside view of the sanitary napkin shown FIG. 1;
FIG. 3A is a sectional view of X-X of the sanitary napkin shown
FIG. 1;
FIG. 3B is a partially enlarged view of the sanitary napkin shown
FIG. 3A;
FIG. 4 is a partially enlarged view of another shape of the
sanitary napkin according to a second embodiment;
FIG. 5 is a sectional view of another shape of the sanitary napkin
according to the first embodiment;
FIG. 6A is a schematic view illustrating a deformed state of the
sanitary napkin according to the first embodiment;
FIG. 6B is a schematic view illustrating a deformed state of the
sanitary napkin according to the first embodiment;
FIG. 7A is a sectional view showing a relationship of the
compressed channels and slip-stoppers of the sanitary napkin
according to the first embodiment;
FIG. 7B is a sectional view showing a relationship of the
compressed channels and slip-stoppers of the sanitary napkin
according to the first embodiment;
FIG. 8 is a partially enlarged view of a sanitary napkin according
to the second embodiment of the present invention;
FIG. 9 is a plan view of a sanitary napkin according to a third
embodiment of the present invention;
FIG. 10A is a sectional view illustrating a sanitary napkin
according to the third embodiment of the present invention;
FIG. 10B is a partially enlarged view of a middle sheet of the
sanitary napkin according to the third embodiment;
FIG. 11 is a view of opening holes in each layer of the sanitary
napkin of the third embodiment when forming a convex-shaped core
portion;
FIG. 12 is a view of another embodiment of the sanitary napkin
according to the third embodiment;
FIG. 13 is a partially enlarged view of a tissue of the sanitary
napkin according to the third embodiment;
FIG. 14 is a view of an embossed roll;
FIG. 15A is a view of an embossed pattern on a top embossed
roll;
FIG. 15B is a view of an embossed pattern on a bottom embossed
roll;
FIG. 16 is a view of an engagement of the embossed rolls of FIGS.
15A and 15B with the sanitary napkin;
FIG. 17A is a sectional view of the embossed pattern through the
line X-X shown in FIG. 15A;
FIG. 17B is a sectional view of the embossed pattern through the
line Z-Z shown in FIG. 15A;
FIG. 17C is an enlarged view of embossed teeth of the embossed roll
of FIG. 15A;
FIG. 18 is a sectional view of a state of engagement of a sanitary
napkin embossing apparatus according to the first embodiment;
FIG. 19 is a sectional view of a state of engagement of a sanitary
napkin embossing apparatus according to the second embodiment;
FIG. 20 is a view of encroachment positions of the embossed roll of
FIG. 15A;
FIG. 21A is a sectional view illustrating the shape of the embossed
teeth at a portion A of FIG. 20;
FIG. 21B is a sectional view illustrating the shape of the embossed
teeth at a portion B of FIG. 20; and
FIG. 21C is a sectional view illustrating the shape of the embossed
teeth at a portion C of FIG. 20.
In the figures, elements that are repeatedly illustrated are
consistently identified by a single reference numeral.
DETAILED DESCRIPTION OF THE INVENTION
The following explains preferred embodiments of the present
invention with reference to the drawings provided. It should be
noted that the present invention is in no way limited to the
embodiments below, nor is the technical range limited to the
embodiments.
In addition, the absorbent article according to the present
invention is worn at the crotch area of a human body with the
object of absorbing menstrual blood, urine, and discharge from the
womb or the like excreted from the human body, however, the
embodiments below use an example of implementation to a sanitary
napkin with the main object of absorbing menstrual blood excreted
from the vaginal orifice of a female human being. Of the two
surfaces of the absorbent article, one side is a surface that
contacts the skin and faces the area of excretion. The other,
opposite side, is a surface that contacts clothing, regardless of
whether clothing is being worn on the outside.
1. First Embodiment
1-1. General Description
The following explains the overall structure of the absorbent
article of the present invention using the sanitary napkin 1 of the
first embodiment.
As shown in FIGS. 1 to 3B, the sanitary napkin 1, which is the
absorbent article according to the first embodiment of the present
invention, is equipped with a liquid-permeable top sheet 2 that
composes a top surface layer, disposed on the surface that contacts
the wearer's skin; a liquid-impermeable back sheet 3 that composes
a back surface side layer, disposed on the surface that contacts
the clothing of the wearer; and a liquid-retainable absorbent body
4 that composes the absorbent layer, and is enveloped in tissue 7.
Adhesive portions 8 are established on the surface side of the back
sheet 3 that contacts the wearer's clothing. The sanitary napkin 1
is affixed to the wearer's underwear or the like at these adhesive
portions 8. Moreover, in the first embodiment, the sanitary napkin
1 is equipped with a liquid-permeable middle sheet 5 arranged
between the top sheet 2 and absorbent body 4; a side sheet 6 that
composes a portion of the top surface layer; and side flaps W1 and
W2 that extend in the width direction (WD) of the sanitary napkin
1. The side flaps W1 and W2 also have adhesive portions 9.
Furthermore, the sanitary napkin 1 is provided with compressed
channels 11 that are compressed channel portions formed into a
concave shape from the surface side that contact a side of the top
sheet 2 toward the back sheet 3. The sanitary napkin 1 is separated
the absorbent body 4 into a core portion 40 and side portions 41 by
these compressed channels 11. Projections 15, which are back side
channels, are formed on the surface side that contacts the clothing
of the compressed channels 11. Spaces 16, provided on both sides
sandwiching the projections 15, are formed into convex shapes
facing from the surface side that contacts the clothing toward the
surface side that contacts the skin.
1-2. Top Sheet
The top sheet 2 is disposed on the wearer's body side when the
sanitary napkin is in use and contacts the area of excretion. The
entire surface or a portion of the top sheet member 2 can be
liquid-permeable. In addition, that member can be composed of one
sheet member, or it can be composed by adjoining a plurality of
sheet members. In this embodiment, the top sheet 2 may be equipped
with a liquid-permeable region substantially in the center portion
in the width direction (WD) of the sanitary napkin 1, and the end
sides in the width direction (WD) may be covered by a
liquid-impermeable side sheet 6.
The middle sheet 5 allows excreta that have permeated the top sheet
2 to pass into the absorbent body 4, and functions as a cushion
while the sanitary napkin is in use. The absorbent body 4 is
enveloped in the tissue 7, and is equipped with a substantially
oval core 40 substantially in the center of the width direction
(WD) of the sanitary napkin 1. The core 40 is a region surrounded
by the compressed channels 11. Sides 41 are formed on both sides of
the core 40 in the width direction (WD). The core 40 and sides 41
are partitioned by the compressed channels 11. The back sheet 3
uses a liquid-impermeable sheet member to prevent excreta and the
like retained in the absorbent body 4 from leaking to the surface
side that contacts the clothing of the wearer.
1-3. Compressed Channels and Spaces
The compressed channels 11 are disposed to extend in the length
direction (LD) of the sanitary napkin 1 to sandwich the core 40.
Specifically, as shown in FIGS. 3A and 3B, the compressed channels
11 are equipped with concave portions 12 formed by high
compression, and convex portions 13 formed by low compression;
these are formed by consecutively compressing with high and low
pressures.
In addition, the compression channels 11 are equipped on the
surface side that contacts the clothing with projections 15 that
project more to the surface side that contacts the clothing than a
back surface 42 that is the surface side of the core 40 that
contacts the clothing of the wearer. Spaces 16, provided on both
sides sandwiching the projections 15, are formed into concave
shapes facing from the surface side that contacts the wearer's
clothing toward the surface side that contacts the skin.
The spaces 16 in this embodiment are formed at both sides to
sandwich the projections 15; on the surface side on the absorbent
body 4 that contacts the wearer's clothing, they are formed to be
convex shapes to face from the surface side that contacts the
wearer's clothing toward the surface side that contacts the
wearer's skin. The peaks of the spaces 16 are formed to be disposed
2 mm more than the backside surface 42 of the core 40 to the
surface side that contacts the wearer's skin. In the other way, the
differences in heights in the thickness direction (TD) of the
absorbent body 4 between the concave portions 12 formed at the
bottom of the compressed channels 11 and the peaks of the spaces 16
are formed to be 2 mm. Preferably, the differences in heights in
the thickness direction (TD) of the absorbent body 4 between the
concave portions 12 formed at the bottom of the compressed channels
11 and the peaks of the spaces 16 are in a range of 0.5 to 10 mm.
If the differences in height in the thickness direction (TD) of the
absorbent body 4 between the concave portions 12 and the spaces 16
are in a range of 0.5 to 10 mm, it is easier for the projections 15
to enter the spaces 16 formed on surface side of the core 40 that
contacts the wearer's clothing.
It should be noted that in this embodiment, the spaces 16 are
provided on both sides that sandwich projections 15, but it is
acceptable to provide spaces on the core 40 side. Providing spaces
16 at the core 40 side makes it possible for the projections 15 to
bend to the spaces 16 side. In the other way, it is possible for
the projections 15 to incline toward the center of the width
direction (WD) of the sanitary napkin 1 via the spaces 16. This
makes it possible to ensure stable deformations of the projections
15 and the core 40 and to improve adherence to the skin.
The compressed channels 11 are provided with a pair of walls 14
formed by engagement by the embossing apparatus described below.
The walls 14 are formed, for example, when the top sheet 2 and
absorbent body 4 are pressed in the thickness direction (TD) of the
sanitary napkin 1, and there is high tensile stress generated in
substantially the center of the thickness direction (TD) of the
sanitary napkin 1 which elongates the absorbent body 4. The walls
14 with the absorbent body 4 stretched are formed to a low density
in substantially the center. This low-density portion suppresses
the spreading of excreta transferred from the high-density portion,
when the core 40 absorbs excreta.
The compressed channels 11 are formed by consecutively pressing the
top sheet 2 and absorbent body 4 from the surface side that
contacts the wearer's skin and the surface side that contacts the
wearer's clothing, but there is no limitation thereto in the
present invention. It is also acceptable to form the compressed
channels 11 by consecutively compressing each of the surface side
that contacts the wearer's skin and the surface side that contacts
the wearer's clothing only on the absorbent body 4, for example, as
shown in FIG. 5. If the compressed channels 11 are formed only in
the absorbent body 4, the absorbent body 4 is easily deformed
because the top sheet 2 does not apply compression to the absorbent
body 4. It is also acceptable to form the compressed channels 11 by
consecutively compressing each of the surface side that contacts
the wearer's skin and the surface side that contacts the wearer's
clothing for the middle sheet 5 and the absorbent body 4. For
example, if the middle sheet 5 and the absorbent body 4, which is
formed by a synthetic resin fiber or the like, are consecutively
compressed from the surface side that contacts the wearer's skin
and the surface side that contacts the wearer's clothing, it is
easy to retain the projected shape of the compressed channels 11 on
the surface side that contacts the wearer's clothing.
It is acceptable that the compressed channels 11 are provided with
openings in the concave portions 12. By providing these openings,
it is possible for the excreta transferred from the top sheet 2 to
fall into the back sheet 3 provided on the surface side of the core
40 that contacts the wearer's clothing, which is underwear. By
allowing excreta to fall into the back sheet 3, it is possible to
suppress the spreading of excreta to the surface layer that
includes the top sheet 2. Also, it is acceptable to equip openings
in the side walls 14. In such cases, in the same way, it is
possible for the excreta transferred from the top sheet 2 to fall
into the back sheet 3 provided on the surface side of the core 40
that contacts the wearer's clothing, which is underwear. It should
be noted that the openings are preferred to be a size that does not
partition the side walls.
In addition, in this embodiment, adhesive portions 8 are provided
at all positions that correspond to the projections 15 on the
backside surface of the compressed channels 11. However, this is
not to be construed as a limitation in the present invention. It is
acceptable to provide the adhesive portions 8 at positions that
correspond to at least a part of the projections 15.
In this embodiment, adhesive portions 8 for slip prevention are
disposed on the surface side that contacts the wearer's clothing of
the compressed channels 11 on the back sheet 3 so as not to
obstruct convex deformation of the core 40 to the surface side that
contacts the wearer's skin, but the present invention is not
limited thereto. It is acceptable to provide the adhesive portions
8 in a state that includes the center in the length direction (LD)
of the sanitary napkin 1, on the surface side of the back sheet 3
that contacts the wearer's clothing. It is possible to dispose
projections 15 on the surface side that constantly contacts the
wearer's clothing more than the core 40 using hot-melt that bonds
the absorbent body 4 and back sheet 3, and to enable the core 40 to
convexly deform to the underwear 70 joined to the core 40.
In addition, it is acceptable that the backside surface 42 of the
core 40 is detachably bonded to the back sheet 3 with the hot-melt
of the absorbent body 4 and back sheet 3. Specifically, it is
acceptable that at least the back surface of the compressed
channels 11 and back sheet 3 are bonded. This makes it possible for
the back sheet 3 and the backside surface 42 of the core 40 to
separate and form a predetermined space when a compressing force is
applied from the buttocks of the wearer in the width direction
(WD). The projections 15 slip into the space, thereby enabling a
stable deformation of the core 40.
In this way, the sanitary napkin 1 is equipped with the compressed
channels 11 and spaces 16 so it is possible for the core 40 to
convexly deform in a stable manner to the surface side that
contacts the wearer's skin. For example, when a compressing force
is applied by the wearer from the buttocks, a compressing force is
added in the directions of the arrows in FIG. 6A. At that time, the
compressing force is transferred to the core 40 via the compressed
channels 11. Then, as shown in FIG. 6B, because spaces 16 are
provided on both sides the projections 15 move to be deformed
towards the backside surface 42 side of the core 40. Specifically,
the projections 15 move to slip into the spaces 16 formed between
the backside surface 42 of the core 40 that is adjacent to the
projections 15. The projections 15 that move and slip into the
spaces transfer the compressing force to further raise the core 40
from the backside surface 42 of the core 40. This causes the core
40 to deform and project to the surface side that contacts the
wearer's skin, allowing close adherence to the area of excretion of
the wearer.
In addition, the sanitary napkin 1, as shown in FIGS. 7A and 7B, is
fastened to the underwear 70 at the surface side of the compressed
channels 11 that contacts the wearer's clothing, in other words at
the projections 15. This makes it possible to position the
compressed channels 11 on the surface side that contacts the
wearer's clothing more than the core 40 so it is possible for the
core 40 to convexly deform in a stable manner.
Furthermore, the sanitary napkin 1 is attached by the side flaps W1
and W2 folding over to the surface side that contacts the wearer's
clothing of the underwear 70 so that when a compressing force is
applied from the wearer's buttocks in the width direction (WD), for
example, action in the thickness direction (TD) of the sides 41 is
restricted, thereby making it easier for the projections 15 to slip
into the spaces 16, and enabling the sanitary napkin 1 to deform in
a stable manner.
2. Other Embodiments
Other embodiments are explained with reference to FIGS. 8 to 13.
Portions of the following embodiments that are not described are
the same as the first embodiment. Furthermore, when the numbers
that are used in the drawings are the same as the first embodiment,
the same numbers are applied.
2-1. Second Embodiment
A second embodiment of the sanitary napkin 1A is explained with
reference to FIG. 8. A partially expanded view of the compressed
channels 11 of the sanitary napkin 1A is shown in FIG. 8 to
facilitate explanation of the feature of the present invention. As
shown in FIG. 8, the concave portions 12 of the compressed channels
11 in the sanitary napkin 1A according to the second embodiment are
provided more on the surface side of the core 40 that contacts the
wearer's skin than the backside surface 42. In this way, if the
concave portions 12 of the compressed channels 11 are provided to
be more on the surface side of the core 40 that contacts the
wearer's skin than the backside surface 42, it is possible for the
projections 15 to enter the spaces 16 when a compressing force is
applied in the width direction (WD) from the wearer's femoral
region, because spaces are formed on both sides of the compressed
channels 11. This makes it possible to project the core 40 to the
surface side that contacts the wearer's skin.
2-2. Third Embodiment
A third embodiment of the sanitary napkin 1C is explained with
reference to FIGS. 9 to 13.
As shown in FIGS. 9 to 13, in the sanitary napkin 1C of the third
embodiment, a plurality of holes 101, 102, and 103 formed
substantially longitudinally are provided extending in the length
direction (LD) of the sanitary napkin 1C for each of the top sheet
2, the middle sheet 5, and the tissue 7. The holes 101, 102, and
103 are formed to have a slit shape and to be along the compressed
channels 11 in the core 40.
By providing the top sheet 2, middle sheet 5 and tissue 7 with the
holes 101, 102, and 103, the top sheet 2, middle sheet 5 and tissue
7 are able to stretch in the width direction (WD) because the holes
101, 102, and 103 can be pulled in the width direction (WD) and
deform into a substantially diamond shape (see FIG. 11) if the core
is deformed to be a convex shaped. For example, if the core 40 is
deformed into a convex shape by a compressing force generated from
the wearer's buttocks, the holes 101, 102, and 103 widen forming
holes, as shown in FIG. 11, so the convex deformation of the core
40 is not hindered. It should be noted that to form a convex shape
without pushing in the core 40, it is acceptable for at least the
sheet material disposed to be more on the surface side that
contacts the wearer's skin than the absorbent body 4 to be
elastic.
By providing the holes 101, 102, and 103 in each of the top sheet
2, middle sheet 5 and tissue 7, they can be extended or contracted
and expanded in the width direction (WD) of the sanitary napkin 1.
Therefore, the absorbent body 4 is not compressed even when the
core 40 is deformed into a convex shape by a force conducted from
the sides 41. This makes it possible to maintain a low density of
the top sheet 2 and the like. For example, bodily fluids and the
like will not return to the top sheet side even if pressure is
applied by the movement of the wearer after deforming to a convex
shape. In other words, it is possible to reduce discomfort caused
by rewetting. Furthermore, it is possible to reduce the return of
bodily fluids and the like from the absorbent body 4 when deforming
to a convex shape because the top sheet 2 does not compress the
absorbent body 4.
The sanitary napkin 1C can be formed into an uneven corrugated
shape on the top sheet 2, as shown in FIG. 12. This ensures an
amount of extension of the top sheet 2 in the width direction (WD),
and enables the top sheet 2 to extend easily in the width direction
(WD). Furthermore, the tissue 7 that envelops the absorbent body 4
can be provided with a folded portion 71. By providing the folded
portion 71, an ability to extend is imparted if required when
deforming convexly. This enables the absorbent body 4 to extend in
the width direction (WD) the amount that it is allowed to extend.
(See FIG. 13.)
In addition, it is acceptable to implement an elongating means as
described above in all sheet members. If it is considered that the
distance that the sheet member disposed on the outer surface side
that contacts the wearer's skin extends is longer, it is preferably
provided at least on the top surface layer of the surface side that
contacts the wearer's skin. Furthermore, not only treatment of the
sheets is acceptable, but it is also acceptable to use a sheet that
implements coil-shaped crimped fibers, fibers that can stretch,
such as urethane, or to reduce the fusing point of the sheet to
make it easier to extend in the width direction (WD). It is also
acceptable to strengthen the fiber orientation in the length
direction (LD), thereby reducing their tensile strength in the
width direction (WD) and applying extensibility, and implement
extensibility in the width direction (WD) by providing openings. In
addition, it is acceptable to form the sheets and to provide a
predetermined space between the top sheet 2 and the absorbent body
4 without the sheet itself being able to stretch. This makes it
possible to easily bias deformation in the same way as above
because a deformation space is formed for the absorbent body 4 and
the like to deform.
Each of the top sheet 2, the middle sheet 5, and the tissue 7 is
preferred to be bonded by a spiral-shaped hot-melt adhesive so as
not to hinder extending thereof in the width direction. Also, it is
acceptable, for example, to bond these using a spray coating or the
like, or a spiral-shaped hot-melt adhesive extending in the length
direction. Furthermore, it is also acceptable to join each of the
top sheet 2, the middle sheet 5, and the tissue 7 by embossing
between the holes 101 with a predetermined emboss 114, for example.
In such a case, for the shape of the emboss 114, it is acceptable
to join the sheets by forming polygons, ovals, long shapes, and
star shapes, in addition to the substantially circular shapes shown
in FIG. 9. It should be noted that it is preferable not to join
continuously in the width direction in consideration of hindering
the materials ability to stretch.
3. Components
The following explains the components in detail.
3-1. Top Sheet
The top sheet 2 can employ a liquid-permeable sheet to compose the
entire top sheet 2 or a portion thereof. A resin film formed with a
plurality of liquid-permeable holes in the same way as the
liquid-permeable region composes all or a portion of the top sheet
2, with a net-shaped sheet having a plurality of networks, a
liquid-permeable nonwoven fiber or fibers given as examples of the
material that can be used in the top sheet 2. For example,
polypropylene (PP), polyethylene (PE) or polyethylene terephthalate
(PET) can be used to form the resin film or net-shaped sheet. A
cellulose fiber such as rayon, a spun-laced nonwoven fiber formed
of synthetic resin fibers, and through-air type nonwoven fiber
formed using the synthetic resin fibers can be used as the nonwoven
fibers. It is possible to use synthetic fibers of hydrophobic fiber
and hydrophilic fiber as the fiber configuration of the through-air
nonwoven fibers formed with air spaces between internal fibers.
It should be noted that in consideration of liquid penetration, it
is preferred that density control is implemented that disposes
higher density around the vicinity of a portion of the top sheet 2,
an increasing gradient of densities in the top sheet 2 itself, or
to apply differences in hydrophilicity to the top sheet 2.
3-2. Middle Sheet
The middle sheet 5 is disposed between the top sheet 2 and the
absorbent body 4. It plays the roll of a support body for the
absorbent body 4, and as a liquid-permeable sheet that gives the
absorbent body 4 malleability and stability of form. A resin film
formed with a plurality of liquid-permeable holes in the same way
as the liquid-permeable region composes all or a portion of the
middle sheet 5, which is a net-shaped sheet having a plurality of
networks, with a liquid-permeable nonwoven fiber or fibers given as
examples of the material that can be used in the middle sheet 5.
For example, polypropylene (PP), polyethylene (PE) or polyethylene
terephthalate (PET) can be used to form the resin film or
net-shaped sheet. A cellulose fiber such as rayon, a spun-laced
nonwoven fiber formed of synthetic resin fibers, and through-air
type nonwoven fiber formed using the synthetic resin fibers can be
used as the nonwoven fibers. It should be noted that in
consideration of liquid penetration, it is preferred that density
control is implemented that disposes higher density around the
vicinity of a portion of the middle sheet 5, an increasing gradient
of densities in the middle sheet 5 itself, or to apply differences
hydrophilicity to the top sheet 2
3-3. Absorbent Body
As a material used in the absorbent body 4, softwood kraft pulp is
ground and a highly absorbent polymer at a blend of 10% is added
thereto, and enveloped by a tissue. However, the present invention
is not limited to that. For example, it is also acceptable to use a
material that blends thermally adhesive synthetic fibers to the
ground pulp, or material that has been formed into a sheet shape
using the airlaying technique or pulp, a spun-laced nonwoven fiber
composed of cotton, rayon or pulp, or a mixture of these. It is
also acceptable to use a material with elasticity, such as urethane
or a cellulose sponge or the like. It should be noted that the
present invention is in no way limited to the examples provided
above or combinations thereof, and that the present invention can
use any ordinary absorbent body.
3-4. Back Sheet
A material is used in the back sheet 3 that prevents excreta
absorbed in the absorbent body 4 from leaking to the outside. By
using a moisture-vapor permeable material, wearer discomfort and a
sticky feeling when the sanitary napkin is worn are reduced. The
back sheet 3 according the embodiments uses a liquid-impermeable
polyethylene (PE) material, but this is not to be construed as a
limitation to the present invention. For example, it is acceptable
to use a sheet laminated with a resin film made by combining one or
two types of the materials of polyethylene (PE), polypropylene
(PP), polyethylene terephthalate (PET), and EVA resin, to add
filler or the like to the resin film, and stretch it and form
minute holes in the film to make it moisture-vapor permeable. Also
possible are a laminated material of resin and paper, or a sheet
laminated with nonwoven fibers and resin film. Preferably, a
hydrophilic nonwoven fiber, an impermeable plastic film, or
laminated sheet of nonwoven fibers and impermeable plastic film are
used. In addition, it is acceptable to use an SMS nonwoven fiber
that sandwiches a highly waterproof melt-blown nonwoven between a
strong spun-bond nonwoven fiber.
3-5. Adhesive Body
The adhesive used in the slip-prevention adhesive portion 8 and
adhesive portion 9 is a rubber-based hot-melt type, but this is not
a limitation to the present invention. For example, an olefin type
hot-melt, mechanical fasteners, or a styrene rubber based
slip-prevention material can be used.
4. Manufacturing Apparatus
The sanitary napkin 1 according to the present invention is formed
using an embossing apparatus 100 provided with a pair of embossing
rollers 101 and 102, as shown in FIGS. 14 to 16. As shown in FIG.
14, the embossing apparatus 100 is provided with an upper embossing
roller 101 and a lower embossing roller 102. The upper and lower
embossing rollers 101 and 102 each rotate a predetermined number of
times. The sanitary napkin 1 is formed with the compressed channels
11 by passing between the upper embossing roller 101 and the lower
embossing roller 102 while applying a predetermined amount of
pressure and heat thereto.
It should be noted that as shown in FIG. 14, normally when
considering the feeling of the sanitary napkin against the skin,
the sanitary napkin is pressed by the male (convex) upper embossing
roller 101 from the top sheet 2 side, and by the female (concave)
lower embossing roller 102 from the back sheet 3 side to form the
compressed channels 11. In addition, to form the compressed
channels 11, it is preferred that the pressure bonding treatment be
performed under heat and pressure.
As shown in FIG. 15A, the upper embossing roller 101 has the male
(convex) upper embossing pattern 103 formed to a predetermined
shape. As shown in FIG. 15B, the lower embossing roller 102 has the
female (concave) lower embossing pattern 104 formed to a
predetermined shape. As shown in FIG. 16, the compressed channels
11 according to the present invention are formed by each of the
embossing patterns 101 and 102 being pressed into the sanitary
napkin 1. Specifically, the compressed channels 11 are formed by
the embossing teeth 111 of the upper embossing roller 101 and the
female (concave) pattern 112 formed in the lower embossing roller
102 pressing together in the thickness direction (TD) with the
embossing teeth 111 pressing into the female (concave) pattern from
the surface side that contacts the wearer's skin, and the female
(concave) pattern 112 pressing from the surface side that contacts
the wearer's clothing.
Specifically, as shown from FIGS. 17A to 17C, the embossing pattern
103 on the upper embossing roller 101 according to the first
embodiment is provided with embossing teeth 110 and high embossing
teeth 111. The high embossing teeth 111 are provided on both sides
of the substantially oval-shape formed substantially in the center
in the length direction (LD).
The high embossing teeth 111 and embossing teeth 110 are formed to
an uneven shape where convex portions 111A (110A) and concave
portions 111B (110B) are consecutively arranged, as shown in FIG.
17C. The concave portions 12 that are compressed to be high in the
compressed channels 11 are formed by the convex portions 111A
(110A), and the convex portions 13 that are compressed to be low
are formed by the concave portions 111B (110B). It should be noted
that according to the first embodiment, as the high embossing teeth
111 and the embossing teeth 110, an unevenly shaped portion where
the convex portions 111A (110A) and the concave portions 111B
(110B) are consecutively arranged, but this is not to be construed
as a limitation to the present invention. It is also acceptable for
this not to be uneven, but formed to a uniform height.
In addition, an embossing pattern 104 on the lower embossing roller
102 is formed to a female shape (concave shape) to enable the high
embossing teeth 111 of the upper embossing roller 101 to mesh
therein. Specifically, as shown in FIG. 18, projecting portions of
the high embossing teeth 111 are formed to mate with the female
(concave) portion of the engaging concave portion 112.
In addition, as shown in FIG. 19, embossing teeth 112a,
substantially U-shaped in the profile, can be formed on the
embossing pattern 104a of the lower embossing roller 102 by taking
a shape that projects to the embossing teeth 110a on both sides of
the engaging portion to enable engagement with the embossing teeth
110a of the upper embossing roller 101. It should be noted that the
substantially U-shaped embossing teeth 112a are not uneven, but
have a uniform height extending in series. However, the present
invention is not limited to this shape and can use teeth where one
or all have different heights. In other words, it is also
acceptable to use shapes provided with consecutive concave and
convex portions. In other words, the substantially U-shaped
embossing teeth 112a can be intermittently projected and not
consecutive. In this way, it is easier for the shapes of the
projections 15 to be maintained in the compressed channels 11 by
providing concave portions to part or all of the substantially
U-shaped embossing teeth 112a.
According to the first embodiment of the present invention, as
shown in FIG. 18, embossing rollers 101 and 102 having the
following dimensions may be used. For example, the convex portion
pitch A of the upper embossing roller 101 may be 37 mm; the
distance B of the engaging portion of the upper embossing roller
101 and the lower embossing roller 102 may be 0.75 mm; the engaging
depth C for projecting the compressed channels 11 downward may be
3.0 mm; the side wall angle D that opposes the compressed channels
11 of the lower embossing roller 102 may be 90.degree.; and the
distance E from the bottom surface of the upper embossing roller
101 to the bottom surface of the lower embossing roller 102 may be
12 mm.
According to the second embodiment of the present invention, as
shown in FIG. 19, embossing rollers 101 and 102 having the
following dimensions may be used. For example, the convex portion
pitch A of the upper embossing roller 101 may be 37 mm; the
distance B of the engaging portion of the upper embossing roller
101 and the lower embossing roller 102 may be 0.75 mm; the engaging
depth C for projecting the compressed channels 11 downward may be
3.0 mm; the side wall angle D that opposes the compressed channels
11 of the lower embossing roller 102 may be 80.degree.; and the
distance E from the bottom surface of the upper embossing roller
101 to the bottom surface of the lower embossing roller 102 may be
12 mm.
The convex portion pitch A of the upper embossing roller 101 is
preferred to be in a range of 20 to 60 mm, or 30 to 50 mm because
the core 40 deforms to a convex shape. If the convex portion pitch
A is less than 25 mm, the distance from the compressed channels 11
to the center of the core 40 will be too short, which will require
a large force to deform it to a convex shape, so deformation
becomes difficult. If the convex portion pitch A is more than 50
mm, the distance of the compressed channels 11 will be too long,
which will cause bending to occur in the compressed channels 11
while being deformed.
The distance B of the engaging portions of the upper embossing
roller 101 and the lower embossing roller 102 is preferred to be in
a range of 0.3 to 10 mm. More preferable is a range of 0.5 to 5.0
mm. In a case where the distance B of the engaging portions is less
than 0.3 mm, these will not engage well when the basis weight of
the absorbent body 4 is high. In a case where the distance B of the
engaging portions is more than 10 mm, it may not be possible to
form the compressed channels 11 to a projection when the basis
weight of the absorbent body 4 is low.
The engaging depth C to project the compressed channels 11 downward
is preferred to be in a range of 1 to 10 mm. More preferable is a
range of 2 to 6 mm. If the engaging depth C is less than 1 mm, the
engaging concave portions 112 may not be adequately formed and
deformation will not be proper. In addition, if the engaging depth
C is more than 10 mm, the absorbent body 4 of the engaging portions
may be stretched too far to tear the absorbent body 4, and the
compressed channels 11 and core 40 will be difficult to
separate.
The range of the side wall angle D that opposes the compressed
channels 11 of the lower embossing roller 102 is in the range of 30
to 120.degree.. More preferable is the range of 45 to 100.degree..
In a case where the side wall angle D is less than 30.degree., the
forming of the projection of the compressed channels 11 toward the
surface side that contacts the wearer's clothing will not be
adequate. If the side wall angle D is more than 120.degree., the
compressed channels 11 may get caught on the engaging portions
after the engagement and they will not be easily pulled off from
the metal plate (or metal roll), thereby hindering continuous
production.
It is preferred that the distance E from the bottom surface of the
upper embossing roller 101 to the bottom surface of the lower
embossing roller 102 be in a range between 5 to 30 mm. More
preferable is a range of 8 to 15 mm.
In this second embodiment, indentations are formed in the lower
embossing roller 102 that correspond to the upper embossing roller
101; and convex portions are provided on the upper embossing roller
101 that engage the lower embossing roller 102, but the present
invention is not limited to this configuration. The lower embossing
roller 102 can be formed to a flat surface that does not have
concavity or convexity, and be used with a manufacturing apparatus
that uses a material that becomes concave when it is engaged with
the upper embossing roller 101 and be able to realize the same
format. For example, it is acceptable to use a material that
changes in size when compressed, such as paper or a hard
rubber.
In addition, it is acceptable that the engaging concave portion 112
and embossing teeth 110 and 111 that form the compressed channels
11 be different according to the location to form the compressed
channels 11. For example, FIG. 20 shows the positioning of the
engaging concave portion 112 and embossing teeth 110 and 111. As
shown in FIG. 20, the shapes used for the engaging concave portions
112 and embossing teeth 110 and 111 are different because of
portions A, B, and C.
At the portion A, for example, the shapes of the engaging concave
portions 112 and embossing teeth 110 and 111 shown in FIG. 21A are
preferred. In addition, at the portion B, which is positioned near
the area of excretion and differs from the portion A, the most
pressure is received from the wearer's buttocks, so it is necessary
to securely project that toward the surface side that contacts the
wearer's clothing. Therefore, the engaging is stronger than the
peripheral areas, and it is necessary to increase the stretching
distance so that the shapes of the engaging concave portion 112 and
embossing teeth 110 and 111 shown in FIG. 21B are preferred.
Moreover, since a projection is formed at the portion C that
extends in the width direction (WD), it is easy for the absorbent
body 4 to jam in the substantially U-shaped portion of the engaging
portion of the embossing roller 102. Therefore, it is necessary to
provide an incline to the side that contacts the embossing teeth
110 and 111 of the engaging concave portion 112 to make it easier
to pull out the absorbent body 4 after the engagement. For example,
the engaging concave portion 112 of the shapes shown in FIG. 21C
are preferred. Since the embossing extends in the width direction
(WD), the tearing of the sheet is facilitated by providing an angle
to the embossing teeth 111 as shown in FIG. 21C.
5. Manufacturing Method
The manufacturing method of the sanitary napkin 1 according to the
present invention is explained. The manufacturing method of the
sanitary napkin 1 according to the present invention is configured
with a compressed channel forming process that forms the compressed
channels 11 that are concave to the surface side that contacts the
wearer's skin, and spaces that project to the surface side that
contacts the wearer's clothing by pressing the sanitary napkin 1 in
the thickness direction (TD) from both the surface side that
contacts the wearer's skin and the surface side that contacts the
wearer's clothing. This compressed channel forming process has an
upper die roller unit having a convex portion formed to a
predetermined pattern on its surface, and a lower die roller unit
having a concave portion formed to the predetermined pattern that
can engage the convex portion. In addition, the sanitary napkin is
formed by pressing an absorbent article material that includes at
least an absorbent body in the thickness direction (TD).
The sanitary napkin 1 according to the present invention is formed
with compressed channels 11 and spaces 16, the sanitary napkin 1
being passed between the upper die roller and the lower die roller
while applying a predetermined pressure and heat thereto. When the
sanitary napkin passes through, the absorbent article that includes
at least the absorbent body is compressed in the thickness
direction (TD). This compressing can be consecutive or compressed
at predetermined intervals. It should be noted that this
manufacturing method is omitted because it supports the description
of the manufacturing apparatus.
Targets for manufacturing by this manufacturing method are a
substantially longitudinally shaped sanitary napkin 1 having at
least a portion of a liquid-permeable top sheet 2 having a width
direction (WD) and a length direction (LD) that is perpendicular to
the width direction (WD), and is disposed on a surface side that
contacts the wearer's skin; a liquid-impermeable back sheet 3
disposed on a surface side that contacts the wearer's clothing; and
an absorbent body disposed between the top sheet 2 and the back
sheet 3. In addition, compressed channels are formed on the surface
side of the absorbent body that contacts the wearer's skin. The
compressed channels separate the core disposed with the absorbent
body at a center area of the width direction, and the side portions
disposed on both sides of the core in the width direction. The
sanitary napkin forms the surfaces that contact the wearer's
clothing in the compressed channels to project to the surface side
that contacts the wearer's clothing more than the surfaces on the
core that contact the wearer's clothing in the thickness direction
(TD) of the absorbent article.
It is within the scope of the present invention to include all
foreseeable equivalents to the elements of the present invention as
described with reference to FIGS. 1-21C. The examples provided are
not to be interpreted as limiting the invention beyond that which
is claimed.
* * * * *